send a single TX command after setting up all TX frames. This
removes unnecessary register accesses and bus_dmamap_sync(9) calls.
et(4) uses TX interrupt moderation so it's possible to have TX
buffers that were already transmitted but waiting for TX completion
interrupt. If the number of available TX descriptor is less then
1/3 of total TX descriptor, try reclaiming first to get enough free
TX descriptors before setting up TX descriptors.
After r228325, et_txeof() no longer tries to send frames after
reclaiming TX buffers. That change was made to give more chance
to transmit frames in main interrupt handler since we can still
send frames in interrupt handler with RX interrupt. So right
before exiting interrupt hander, after enabling interrupt, try to
send more frames. This gives slightly better performance numbers.
While I'm here reduce number of spare TX descriptors from 8 to 4.
Controller does not require reserved TX descriptors, it was just to
reduce TX overhead. After r228325, driver has much lower TX
overhead so it does not make sense to reserve 8 TX descriptors.
change should make et(4) work on any architectures.
o Remove m_getl inline function and replace it with stanard mbuf
interfaces. Previous code tried to minimize code duplication
but this came from incorrect use of common DMA tag.
Driver may be still use a common RX allocation handler with
additional structure changes but I don't see much point to do
that it would make it hard to understand the code.
o Remove DragonflyBSD specific constant EVL_ENCAPLEN, use
ETHER_VLAN_ENCAP_LEN instead.
o Add bunch of new RX status definition. It seems controller
supports RX checksum offloading but I was not able to make the
feature work yet. Currently driver checks whether recevied
frame is good one or not.
o Avoid a typedef ending in '_t' as style(9) says.
o Controller has no restriction on DMA address space, so there
is no reason to limit the DMA address to 32bit. Descriptor
rings, status blocks and TX/RX buffers now use full 64bit DMA
addressing.
o Allocate DMA memory shared between host and controller as
coherent.
o Create 3 separate DMA tags to be used as TX, mini RX ring and
stanard RX ring. Previously it created a single DMA tag and it
was used to all three rings.
o et(4) does not support jumbo frame at this moment and I still
don't quite understand how jumbo frame works on this controller
so use two RX rings to handle small sized frame and normal sized
frame respectively. The mini RX ring will be used to receive
frames that are less than or equal to 127 bytes. The second RX
ring is used to receive frames that are not handled by the first
RX ring.
If jumbo frame support is implemented, driver may have to choose
better RX scheme by letting the second RX ring handle jumbo
frames. This scheme will mimic Broadcom's efficient jumbo frame
handling feature. However RAM buffer size(16KB) of the
controller is too small to hold 2 jumbo frames, if 9KB
jumbo frame is used, I'm not sure how good performance would it
have.
o In et_rxeof(), make sure to check whether controller received
good frame or not. Passing corrupted frame to upper layer is
bad idea.
o If driver receives a bad frame or driver fails to allocate RX
buffer due to resource shortage condition, reuse previously
loaded DMA map for RX buffer instead of unloading/loading RX
buffer again.
o et_init_tx_ring() never fails so change return type to void.
o In watchdog handler, show TX DMA write back status of errored
frame which could be used as a clue to debug watchdog timeout.
o Add missing bus_dmamap_sync() in various places such that et(4)
should work with bounce buffers(e.g. PAE).
o TX side bus_dmamap_load_mbuf_sg(9) support.
o RX side bus_dmamap_load_mbuf_sg(9) support.
o Controller has no DMA alignment limit in RX buffer so use
m_adj(9) in RX buffer allocation to make IP header align on 2
bytes boundary. Otherwise it would trigger unaligned access
error in upper layer on strict alignment architectures.
One of down side of controller is it provides limited set of RX
buffer length like most Intel controllers. This is not problem
at this moment because driver does not support jumbo frame yet
but it may require alignment fixup code to support jumbo frame
on strict alignment architectures.
o In et_txeof(), don't zero TX descriptors for transmitted frames.
TX descriptors don't need write access after transmission.
Driver sets IFF_DRV_OACTIVE when the number of available TX
descriptors are less than or equal to ET_NSEG_SPARE. Make sure
to clear IFF_DRV_OACTIVE only when the number of available TX
descriptor is greater than ET_NSEG_SPARE.
driver that has high precedence for the controller override et(4).
Add missing callout_drain(9) in device detach and rework detach
routine. While I'm here use rman_get_rid(9) instead of using
cached resource id because bus methods are free to change the
id.
While I'm here remove initializing if_mtu, it is set by
ether_ifattach(9). Also move callout_init_mtx(9) to the right below
driver lock initialization.
descriptors before trying to send frames. If we're not able to
send a frame, make sure to prepend it to if_snd queue such that
alt(4) should work.
While I'm here prefer ETHER_BPF_MTAP to BPF_MTAP. ETHER_BPF_MTAP
should be used for controllers that support VLAN hardware tag
insertion. The controller supports VLAN tag insertion but lacks
VLAN tag stripping in RX path though.
one. Interestingly, these are actually the default for quite some time
(bus_generic_driver_added(9) since r52045 and bus_generic_print_child(9)
since r52045) but even recently added device drivers do this unnecessarily.
Discussed with: jhb, marcel
- While at it, use DEVMETHOD_END.
Discussed with: jhb
- Also while at it, use __FBSDID.
(reporting IFM_LOOP based on BMCR_LOOP is left in place though as
it might provide useful for debugging). For most mii(4) drivers it
was unclear whether the PHYs driven by them actually support
loopback or not. Moreover, typically loopback mode also needs to
be activated on the MAC, which none of the Ethernet drivers using
mii(4) implements. Given that loopback media has no real use (and
obviously hardly had a chance to actually work) besides for driver
development (which just loopback mode should be sufficient for
though, i.e one doesn't necessary need support for loopback media)
support for it is just dropped as both NetBSD and OpenBSD already
did quite some time ago.
- Let mii_phy_add_media() also announce the support of IFM_NONE.
- Restructure the PHY entry points to use a structure of entry points
instead of discrete function pointers, and extend this to include
a "reset" entry point. Make sure any PHY-specific reset routine is
always used, and provide one for lxtphy(4) which disables MII
interrupts (as is done for a few other PHYs we have drivers for).
This includes changing NIC drivers which previously just called the
generic mii_phy_reset() to now actually call the PHY-specific reset
routine, which might be crucial in some cases. While at it, the
redundant checks in these NIC drivers for mii->mii_instance not being
zero before calling the reset routines were removed because as soon
as one PHY driver attaches mii->mii_instance is incremented and we
hardly can end up in their media change callbacks etc if no PHY driver
has attached as mii_attach() would have failed in that case and not
attach a miibus(4) instance.
Consequently, NIC drivers now no longer should call mii_phy_reset()
directly, so it was removed from EXPORT_SYMS.
- Add a mii_phy_dev_attach() as a companion helper to mii_phy_dev_probe().
The purpose of that function is to perform the common steps to attach
a PHY driver instance and to hook it up to the miibus(4) instance and to
optionally also handle the probing, addition and initialization of the
supported media. So all a PHY driver without any special requirements
has to do in its bus attach method is to call mii_phy_dev_attach()
along with PHY-specific MIIF_* flags, a pointer to its PHY functions
and the add_media set to one. All PHY drivers were updated to take
advantage of mii_phy_dev_attach() as appropriate. Along with these
changes the capability mask was added to the mii_softc structure so
PHY drivers taking advantage of mii_phy_dev_attach() but still
handling media on their own do not need to fiddle with the MII attach
arguments anyway.
- Keep track of the PHY offset in the mii_softc structure. This is done
for compatibility with NetBSD/OpenBSD.
- Keep track of the PHY's OUI, model and revision in the mii_softc
structure. Several PHY drivers require this information also after
attaching and previously had to wrap their own softc around mii_softc.
NetBSD/OpenBSD also keep track of the model and revision on their
mii_softc structure. All PHY drivers were updated to take advantage
as appropriate.
- Convert the mebers of the MII data structure to unsigned where
appropriate. This is partly inspired by NetBSD/OpenBSD.
- According to IEEE 802.3-2002 the bits actually have to be reversed
when mapping an OUI to the MII ID registers. All PHY drivers and
miidevs where changed as necessary. Actually this now again allows to
largely share miidevs with NetBSD, which fixed this problem already
9 years ago. Consequently miidevs was synced as far as possible.
- Add MIIF_NOMANPAUSE and mii_phy_flowstatus() calls to drivers that
weren't explicitly converted to support flow control before. It's
unclear whether flow control actually works with these but typically
it should and their net behavior should be more correct with these
changes in place than without if the MAC driver sets MIIF_DOPAUSE.
Obtained from: NetBSD (partially)
Reviewed by: yongari (earlier version), silence on arch@ and net@
controller also has support for IP/TCP checksum offloading for Rx
path. But I failed to find to way to enable Rx MAC to compute the
checksum of received frames.
both big-endian and little-endian format in descriptors for Rx path
but I couldn't find equivalent feature in Tx path. So just stick to
little-endian for now.
directly access them at fixed address. Frequently the register
offset could be changed if additional PCI capabilities are added to
controller.
One odd thing is ET_PCIR_L0S_L1_LATENCY register. I think it's PCIe
link capabilities register but the location of the register does
not match with PCIe capability pointer + offset. I'm not sure it's
shadow register of PCIe link capabilities register.
IF_ADDR_UNLOCK() across network device drivers when accessing the
per-interface multicast address list, if_multiaddrs. This will
allow us to change the locking strategy without affecting our driver
programming interface or binary interface.
For two wireless drivers, remove unnecessary locking, since they
don't actually access the multicast address list.
Approved by: re (kib)
MFC after: 6 weeks
